It happens to me all the time.
The other day, I said that my friend was a hopeless romantic because he was longing to talk with his girlfriend, but she broke up with him fast. The exact second after I said it, and before Austin relied, I realised that it would sound like an insult to him. It did, and I depressed him even more by accident.
('-_-) <-- embarrassed Japanese emoticon
Sometimes I still mentally cringe about social faux pas I made years ago.

I usually have tact and insight in dealing with people I already know, but around new people I can be clueless and unintentionally insulting. This is because I tend to walk around on a kind of automatic pilot. Once I have assimilated new people & situations into my mind, I know how to behave myself, but until then, I tend to goof up. I went to a dog show several years ago, met a Saint Bernard who was competing there, and enthusiastically told his owner, "Oh, he has a head like a pumpkin!" How surprised I was when she scowled and said, "I take offense to that!" :?
Maybe she had a head like a pumpkin too. I don't know why she took offence as pumpkins are pretty cool.

Pumpkins ARE cool! :grin: She was probably just tense about the competition, as many people are at these shows, and wasn't in the mood for my chatter. That's where most of my mistakes come from: being so absorbed in my train of thought that I don't tune in to my surroundings. But I am learning!

Well she was the one being rude, not you.
And I think with our condition, we do have this tendency to obsess over things like this.
I feel the same way and when thinking about some of the things that have happened years ago I have exactly the same sense of embarassment as I would if they had happened yesterday. Every day I tend to obsess over different social interactions I've had and whether or not I've said and done the right things and what other people's impressions of me might be.
In my oppinion, the words "hi/hello" is a word used to introduce one's self to another person they just met or don't know very well. You certainly wouldn't need to say it to your sister, and if you don't want to say it to her friend, then I believe you don't have to. If the friend takes it personaly, then maybe she mas some emotional issues to work out with herself because that would be a bit too sensitive.
As for Gareth, I havn't had any problem with him. I can understand if there is caution after what they say happened. I have no proof however, so please don't think I am picking sides. I don't pick sides or quick friends. Personal questions? If so, I don't see why I havn't been asked the same. I stand as much a chance of being a troll as anyone else. I'm not one, at least not on purpose.

Someone posted at saying Gareth made a "rude" mistake, and that they wanted someone to petition him so they could get back into chat. Uhm, why?
The thread wasn't about the chat room, but they wanted to bring it in anyway. I just put my reply like that to put my oppinion, as I tend to do.
Well, it was errased I see. So now, my last reply looks wierd. Too bad I can't edit for that reason.
I usually have tact and insight in dealing with people I already know, but around new people I can be clueless and unintentionally insulting. This is because I tend to walk around on a kind of automatic pilot. Once I have assimilated new people & situations into my mind, I know how to behave myself, but until then, I tend to goof up. I went to a dog show several years ago, met a Saint Bernard who was competing there, and enthusiastically told his owner, "Oh, he has a head like a pumpkin!" How surprised I was when she scowled and said, "I take offense to that!" :?
I can't even begin to tell you how familiar that is. A few friends of mine once took great offense because I tend to use fewer and smaller words when talking. So when I said that their gift to me was really great because 'it took thought, a little time, some cleverness and was cheap' rather than saying 'didn't cost much' I insulted them. Geez, can't they figure this out from context? Okay, I learned something from that. I repeated that kind of miskate a few times before I learned how to listen to how other people say things like that.
Besides, I think pumpkins are cool! 
"Oh yeah! I forgot to say hello again".
I often forget to say hello to someone who just came in and who will not directly deal with me (f.x., I'm just going to do some another thing). And I never realize it as a mistake until some of my relatives points it out. I think I learned my lesson but next time we have guests in the house it repeats again and again.
I've made it a habit to at least wave to someone I recognize, or smile and nod, especially if I'm in a conversation with someone else. It's a lot easier than "risking a conversation" sometimes.
I believe that this topic may have been mislabled - should it not be "Realizing you have been misunderstood"? We know what we meant when we said it even if the receiver did not. I think that tenaciouscj made a good point about the 'pumpkin episode'. It was the dog's owner who misunderstood the remark and her error should not cause couldbecousin discomfort when, in fact, he was paying the dog a complement. When I am misunderstood I try to 'dumb it down' for the NT who is not getting it. I no longer take responsibility for other peoples insecurities and they are responsible for their own feelings. If they take offense to what I say, misunderstood or not, the oneous is on them to ask for clarification, not have a hissy fit. Its logical and mature behaviour and nothing to be ashamed of or beat yourselves up about.
By point of fact, I agree completely. Most people, however (and most people are NTs or we wouldn't call them "typical") don't act logically. The onus then falls on us to _try_ to make them understand that they misunderstood. Like by us saying, "I think you misunderstood me."
Sad, but true. Einstein said it well: "In theory, theory and practice are the same. In practice, they're different." I learn a lot from old Al.
In my oppinion, the words "hi/hello" is a word used to introduce one's self to another person they just met or don't know very well. You certainly wouldn't need to say it to your sister, and if you don't want to say it to her friend, then I believe you don't have to. If the friend takes it personaly, then maybe she mas some emotional issues to work out with herself because that would be a bit too sensitive.
I relate it more like saluting in the military. If you've been in the same area with them all day, then you only do it the first time you see them that day. If they've been gone for hours, do it again.
If you live with them, then "where the he// have you been all morning" may be more appropriate!

No, people you live with don't need a "hello," but "good morning" or "out late last night?" or something is still appropriate. NT's are chatty and they expect everyone to be. The call it "being nice," but there's something deeper behind it, I think. Far too many of them fear silence, which is one reason why there are TVs in every room, radios going, subwoofers in the trunk, etc; and why there's always at least one of them turned on.
When I was first boarding, I got into so much trouble for not saying "good morning" to the lady of the house. I don't know why I didn't say it apart from shyness. I wasn't trying to be rude but she was upset so I did my best to change that behaviour as it was something that could have hurt others too.
AWF, thanks for your kind remarks. Pumpkins are indeed beautiful. I got a funny look because I once described a baby boy as "beautiful".